Heat dissipation module and portable device having the heat dissipation module

ABSTRACT

A heat dissipation module for lowering the temperature of a heating element is disclosed. The heat dissipation module comprises a heat dissipation module body, a container, and a liquid element. The heat dissipation module body is made of a heat conductive material; the container is installed in the heat dissipation module body; and the liquid element is disposed in the container. Therefore, when the heat dissipation module is in contact with the heating element, heat generated by the heating element is absorbed by the heat dissipation module body and the liquid element.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipation module and aportable device; more particularly, the present invention relates to aheat dissipation module and a portable device having the capability oflowering the temperature of a heating element.

2. Description of the Related Art

Generally, an electronic device comprises various kinds of circuitboards, and each circuit board has various kinds of heating elements(such as a chip). When the heating element is working, it generates ahuge amount of heat, thereby increasing its temperature. If the heatcannot be effectively and immediately dissipated, the operation of theelectronic device may be affected. More seriously, the heating elementmight be damaged due to overheating. In order to ensure that the heatingelement can work properly, it is common practice to install a heatdissipation module on the heating element, so as to conduct the heatgenerated by the heating element to the heat dissipation module andthereby achieve the object of lowering the temperature of the heatingelement.

There are two major types of heat dissipation modules—an active heatdissipation module and a passive heat dissipation module. An active heatdissipation module, such as a cooling fan or a water-cooling device,needs additional driving energy to perform a heat dissipation action. Apassive heat dissipation module, such as a cooling fin, does not needadditional driving energy. Although an active heat dissipation modulehas a better heat dissipation effect than that of a passive heatdissipation module, an active heat dissipation module has a higher costand needs a larger space for installation. Therefore, an active heatdissipation module is more suitable for installation in a large-scaleelectronic device (such as the motherboard of a desktop computer). As aresult, the scope of applications of an active heat dissipation moduleis much smaller than that of a passive heat dissipation module.

With regard to a modern passive heat dissipation module, in order toenhance its heat dissipation effect, a layer of thermal grease isapplied on a surface of the passive heat dissipation module that is incontact with the heating element so as to increase the heatconductivity; in addition, the volume of the passive heat dissipationmodule is enlarged to absorb more heat, or the passive heat dissipationmodule is designed with fin-like protrusions so as to increase thesurface area for heat dissipation.

However, because a passive heat dissipation module is usually made ofmetal, the following drawbacks are inherent in practical productionapplications: (1) Because the specific heat of metal is low, the passiveheat dissipation module and the heating element reach thermalequilibrium in a short amount of time, which makes the temperature ofthe heating element rise or fall very quickly; such rapid changes intemperature result in a thermal impact on the heating element and mayeasily damage the heating element. (2) Because some of the circuitboards of an electronic device need to be vertically installed, theweight of a passive heat dissipation module made of metal, due to thehigher specific gravity, might cause the circuit boards to bend andthereby affect the reliability of the electronic device.

In the known prior art, such as Taiwan Patent No. I308047 (Heatdissipation device), a heat dissipation device is disclosed for beingused to dissipate heat of an electronic element. The heat dissipationdevice comprises a heat absorbing portion, a heat dissipating portionjointed with the heat absorbing portion, and a heat storage body jointedwith the heat absorbing portion. The heat storage body is a containermade of a heat conductive material, and is filled with a phase changematerial. The phase change material is solid at a normal temperature,and changes from solid to liquid upon being heated. The heat absorbingportion is a base which is directly contacted to a heating electronicelement. The heat dissipating portion is a heat sink set disposed on theheat absorbing portion. However, although the known prior art disclosesthat the heat storage body can be filled with the phase change material,it still has the following drawbacks: (1) The jointed surface areabetween the heat storage body and the heat absorbing portion is limited;as a result, the heat dissipation efficiency of the heat storage body islowered; and (2) the phase change temperature of the phase changematerial is fixed and thus cannot change with the temperature of theheating electronic element.

Therefore, there is a need to provide a heat dissipation module andportable device having the heat dissipation module to mitigate and/orobviate the aforementioned problems.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a heat dissipation moduleand a portable device having the same for lowering the temperature of aheating element.

To achieve the abovementioned object, the heat dissipation module of theinvention comprises a heat dissipation module body, a container, and aliquid element. The heat dissipation module body is made of a heatconductive material; the container is installed in the heat dissipationmodule body; and the liquid element is disposed in the container.Therefore, when the heat dissipation module is in contact with theheating element, heat generated by the heating element can be absorbedby the heat dissipation module body and the liquid element, so as toachieve an effect of lowering the temperature of the heating element. Inone embodiment of the invention, the liquid element is water.

To achieve the abovementioned object, the portable device of theinvention comprises at least one heating element and at least one heatdissipation module. The at least one heat dissipation module isconnected to the at least one heating element. The at least one heatdissipation module comprises a heat dissipation module body, acontainer, and a liquid element. The heat dissipation module body ismade of a heat conductive material; the container is installed in theheat dissipation module body; and the liquid element is disposed in thecontainer. Therefore, when the heat dissipation module is in contactwith the heating element, heat generated by the heating element can beabsorbed by the heat dissipation module body and the liquid element, soas to achieve an effect of lowering the temperature of the heatingelement. In one embodiment of the invention, the liquid element iswater.

Other objects, advantages, and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the invention will becomeapparent from the following description of the accompanying drawings,which disclose several embodiments of the invention. It is to beunderstood that the drawings are to be used for purposes of illustrationonly, and not as a definition of the invention.

In the drawings, wherein similar reference numerals denote similarelements throughout the several views:

FIG. 1 illustrates a schematic drawing of a portable device according toone embodiment of the invention.

FIG. 2 illustrates a structural drawing of a heat dissipation moduleaccording to one embodiment of the invention.

FIG. 3 illustrates a structural drawing of the heat dissipation moduleaccording to another embodiment of the invention.

FIG. 4 illustrates a structural drawing of the heat dissipation moduleaccording to yet another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Please refer to FIG. 1 and FIG. 2 of a heat dissipation module and aportable device having the heat dissipation module according to oneembodiment of the invention. FIG. 1 illustrates a schematic drawing ofthe portable device according to one embodiment of the invention, andFIG. 2 illustrates a structural drawing of the heat dissipation moduleaccording to one embodiment of the invention.

As shown in FIG. 1, the portable device 5 of the invention comprises atleast one heating element 51 and at least one heat dissipation module 1.The at least one heating element 51 is installed in, but is not limitedto, a circuit board 52 of the portable device 5. The at least one heatdissipation module 1 is connected to the at least one heating element51. In one embodiment of the invention, a layer of thermal grease (notshown in the figures) is applied on the surface of the heat dissipationmodule 1 that makes physical contact with the heating element 51 so asto enhance the heat conductivity efficiency, but please note that thescope of the invention is not limited to the above description. In oneembodiment of the invention, the heating element 51 is, but is notlimited to, a chip or other heating device of the portable device 5. Inone embodiment of the invention, the heat dissipation module 1 is, butis not limited to, a passive heat dissipation module.

As shown in FIG. 1, in one embodiment of the invention, the portabledevice 5 is, but is not limited to, a mobile phone. For example, theportable device 5 can also be a personal digital assistant (PDA), a gameconsole, a navigation device, or the like. Please note that in thefollowing embodiment, the heat dissipation module 1 is applied to theportable device 5; however, the heat dissipation module 1 of theinvention can be applied to any heating element 51 capable of generatingheat without being limited to application to the portable device 5.

As shown in FIG. 2, the heat dissipation module 1 of the inventioncomprises a heat dissipation module body 10, a container 20, and aliquid element 30. The heat dissipation module body 10 comprises aplurality of fins 11; the container 20 is installed in the heatdissipation module body 10; and the liquid element 30 is disposed in thecontainer 20. Therefore, when the heat dissipation module 1 is incontact with the heating element 51, heat generated by the heatingelement 51 can be absorbed by the heat dissipation module body 10 andthe liquid element 30, so as to achieve an effect of lowering atemperature of the heating element 51. The fins 11 are used forincreasing the surface area of the heat dissipation module 1 for heatdissipation.

In one embodiment of the invention, the heat dissipation module body 10is made of a heat conductive material, and the heat conductive materialis selected from, but is not limited to, the following material groups:aluminum, aluminum alloy, copper, copper alloy, silver, and silveralloy.

In order to solve the problem that the heat dissipation module 1 and theheating element 51 reach thermal equilibrium in a short amount of timedue to a low specific heat of the metal, as mentioned in known priorarts, in one embodiment of the invention, the liquid element is water,such that it takes longer for the heat dissipation module 1 and theheating element 51 to reach thermal equilibrium because water has thecharacteristics of a higher specific heat and higher heat ofvaporization, and therefore the influence of thermal impact on theheating element 51 can be reduced. Further, because the specific gravityof water (1 g/cm³) is lower than that of most metal materials (forexample, the specific gravity of copper is 8.9 g/cm³), a larger volumeof the container 20 will allow more water to be contained, and theweight of the heat dissipation module 1 can further be reduced, so as toavoid the drawback that the circuit board 52 is bent due to the weightof the heat dissipation module 1, as mentioned in known prior arts.Please note that the liquid element 30 is not limited to water; theliquid element 30 can be any liquid that has a high specific heat andhigh heat of vaporization.

The vaporization temperature of water at 1 standard atmospheric pressure(atm) is 100□, but most of the time, the thermal equilibrium temperatureof the heating element 51 and the heat dissipation module 1 remainsbelow 100□. In order to make the vaporization temperature of water matchthe thermal equilibrium temperature of the heating element 51 and theheat dissipation module 1, the invention provides a mechanism capable ofchanging the vaporization temperature of the liquid element 30 of theheat dissipation module 1.

As shown in FIG. 2, in one embodiment of the invention, the container 20comprises a port 21. The port 21 is disposed on the exterior of the heatdissipation module body 10. The heat dissipation module 1 furthercomprises an on/off element 40. The on/off element 40 is separatelyconnected to the port 21. In one embodiment of the invention, the on/offelement 40 can be, but is not limited to, a pressure valve or a bolt.The liquid element 30 can be infused into the container 20 via the port21, and the pressure of the liquid element 30 can reach a specificexternal pressure via the port 21. More precisely, the heat dissipationmodule 1 can be placed in a space (not shown in the figures) at aspecific pressure, wherein the space has a specific external pressurewith regard to the heat dissipation module 1. When the on/off element 40is not connected to the port 21, the pressure of the liquid element 30will gradually reach the specific external pressure. Therefore, thepressure of the liquid element 30 can be changed, so as to accordinglychange the vaporization temperature of the liquid element 30. In oneembodiment of the invention, the pressure of the liquid element 30 issubstantially between 0.4 and 1 atm. Please note that the correlationbetween the pressure and the vaporization temperature of the liquidelement 30 can be found by means of referring to the third-phase diagramof the liquid element 30. Because the technique of utilizing thepressure to change the vaporization temperature or solidificationtemperature of a material is widely and commonly applied by thoseskilled in the art, and this is not the major characteristic of theinvention, there is no need for further description.

Please refer to FIG. 3; in another embodiment of the invention, thecontainer 20 a is a multi-layer structure installed in the heatdissipation module body 10 a, so as to increase the contact area of thecontainer 20 a and the heat dissipation module body 10 a and therebyincrease the heat conductivity efficiency of the heat dissipation module1 a.

Please refer to FIG. 4; in yet another embodiment of the invention, thecontainer 20 b is an S-shaped structure installed in the heatdissipation module body 10 b, so as to increase the contact area of thecontainer 20 b and the heat dissipation module body 10 b and therebyincrease the heat conductivity efficiency of the heat dissipation module1 b.

According to the above description, the heat dissipation module 1 of theinvention has the following advantages: (1) extending the time ofreaching thermal equilibrium so as to prolong the usage life of theportable device; and (2) reducing the weight of the heat dissipationmodule.

Although the invention has been explained in relation to its preferredembodiments, it is to be understood that many other possiblemodifications and variations can be made without departing from thespirit and scope of the invention as hereinafter claimed.

1. A heat dissipation module, used for lowering the temperature of aheating element, the heat dissipation module comprising: a heatdissipation module body, made of a heat conductive material; acontainer, installed in the heat dissipation module body; and a liquidelement, disposed in the container; wherein when the heat dissipationmodule is in contact with the heating element, heat generated by theheating element is absorbed by the heat dissipation module body and theliquid element so as to achieve an effect of lowering the temperature ofthe heating element.
 2. The heat dissipation module as claimed in claim1, wherein the pressure of the liquid element is substantially between0.4 and 1 standard atmospheric pressure (atm).
 3. The heat dissipationmodule as claimed in claim 1, wherein the container comprises a port,which is disposed on the exterior of the heat dissipation module body,the heat dissipation module further comprising an on/off element, whichis separately connected to the port, and the pressure of the liquidelement can reach a specific external pressure via the port.
 4. The heatdissipation module as claimed in claim 1, wherein the container is amulti-layer or S-shaped structure installed in the heat dissipationmodule body.
 5. The heat dissipation module as claimed in claim 1,wherein the liquid element is water.
 6. The heat dissipation module asclaimed in claim 1, wherein the heat dissipation module body comprises aplurality of fins.
 7. The heat dissipation module as claimed in claim 1,wherein the heat conductive material is selected from the followingmaterial groups: aluminum, aluminum alloy, copper, copper alloy, silverand silver alloy.
 8. The heat dissipation module as claimed in claim 1,wherein the heat dissipation module is a passive heat dissipationmodule.
 9. A portable device, comprising: at least one heating element;and at least one heat dissipation module, connected to the at least oneheating element, the at least one heat dissipation module comprising: aheat dissipation module body, made of a heat conductive material; acontainer, installed in the heat dissipation module body; and a liquidelement, disposed in the container; wherein when the heat dissipationmodule is in contact with the heating element, heat generated by theheating element is absorbed by the heat dissipation module body and theliquid element so as to achieve an effect of lowering the temperature ofthe heating element.
 10. The portable device as claimed in claim 9,wherein the pressure of the liquid element is substantially between 0.4and 1 standard atmospheric pressure (atm).
 11. The portable device asclaimed in claim 10, wherein the container comprises a port, which isdisposed on the exterior of the heat dissipation module body, the heatdissipation module further comprising an on/off element, which isseparately connected to the port, and the pressure of the liquid elementcan reach a specific external pressure via the port.
 12. The portabledevice as claimed in claim 9, wherein the container is a multi-layer orS-shaped structure installed in the heat dissipation module body. 13.The portable device as claimed in claim 9, wherein the liquid element iswater.
 14. The portable device as claimed in claim 9, wherein the heatconductive material is selected from the following material groups:aluminum, aluminum alloy, copper, copper alloy, silver, and silveralloy.
 15. The portable device as claimed in claim 9, wherein the heatdissipation module body comprises a plurality of fins.